Fingerprint recognition module, driving method thereof, manufacturing method thereof and display device

Abstract

The present disclosure provides a fingerprint recognition module, a driving method thereof, a manufacturing method thereof, and a display device. The fingerprint recognition module includes a receiving electrode layer, a piezoelectric material layer, and a driving electrode layer. The receiving electrode layer includes a plurality of receiving electrodes arranged in an array along a first direction and a second direction. The piezoelectric material layer is disposed on a side of the receiving electrode layer. The driving electrode layer is disposed on a side of the piezoelectric material layer remote from the receiving electrode layer and includes a plurality of driving electrodes arranged along the second direction. Each driving electrode is a strip electrode extending along the first direction, and overlaps with multiple receiving electrodes arranged along the first direction.

What is claimed is: 
     
       1. A fingerprint recognition module, comprising:
 a receiving electrode layer comprising a plurality of receiving electrodes arranged in an array along a first direction and a second direction intersecting with the first direction; 
 a piezoelectric material layer disposed on a side of the receiving electrode layer; and 
 a driving electrode layer disposed on a side of the piezoelectric material layer remote from the receiving electrode layer and comprising a plurality of driving electrodes arranged along the second direction, 
 wherein each of the plurality of driving electrodes is a strip electrode extending along the first direction, and an orthographic projection of the each of the plurality of driving electrodes on the piezoelectric material layer at least partially overlaps with an orthographic projection of multiple receiving electrodes arranged along the first direction on the piezoelectric material layer; 
 the plurality of receiving electrodes comprise a plurality of receiving electrode groups arranged along the second direction, wherein each of the plurality of receiving electrode groups comprises at least two receiving electrodes arranged along the first direction; 
 the orthographic projection of the each of the plurality of driving electrodes on the piezoelectric material layer at least partially overlaps with an orthographic projection of least two of the plurality of receiving electrode groups on the piezoelectric material layer; and 
 a minimum arrangement period of the plurality of driving electrodes arranged along the second direction is substantially equal to half a wavelength of an ultrasonic wave emitted from the fingerprint recognition module during operation. 
 
     
     
       2. The fingerprint recognition module according to  claim 1 , wherein:
 the minimum arrangement period of the plurality of driving electrodes arranged along the second direction is one of a plurality of distance values that are integer multiples of a minimum arrangement period of the plurality of receiving electrodes arranged along the second direction, which is a distance value closest to half the wavelength of the ultrasonic wave emitted from the fingerprint recognition module during operation; 
 wherein there is a gap between adjacent receiving electrodes, and a range of a ratio R of a width of the gap along the second direction to the minimum arrangement period of the plurality of receiving electrodes arranged along the second direction is: O<R≤20%. 
 
     
     
       3. The fingerprint recognition module according to  claim 1 , wherein
 a width of each of the plurality of driving electrodes along the second direction is less than or equal to half the wavelength of the ultrasonic wave emitted from the fingerprint recognition module during operation. 
 
     
     
       4. The fingerprint recognition module according to  claim 1 , wherein the driving electrode layer further comprises a barrier wall located between two adjacent driving electrodes. 
     
     
       5. The fingerprint recognition module according to  claim 4 , wherein a size of each of the plurality of driving electrodes in a direction perpendicular to the driving electrode layer ranges from 1 micron to 20 microns, and a size of the barrier wall in the direction perpendicular to the driving electrode layer is greater than or equal to the size of each of the plurality of driving electrodes in the direction perpendicular to the driving electrode layer. 
     
     
       6. The fingerprint recognition module according to  claim 1 , wherein the piezoelectric material layer comprises a plurality of sub-piezoelectric material layers arranged along the second direction,
 wherein the plurality of sub-piezoelectric material layers are disposed in one-to-one correspondence with the plurality of driving electrodes. 
 
     
     
       7. The fingerprint recognition module according to  claim 1 , further comprising:
 a reflective layer located on a side of the driving electrode layer remote from the piezoelectric material layer; and 
 an insulating layer located between the reflective layer and the driving electrode layer. 
 
     
     
       8. The fingerprint recognition module according to  claim 1 , wherein
 each of the plurality of driving electrodes comprises a first sub-driving electrode in contact with the piezoelectric material layer and a second sub-driving electrode on a side of the first sub-driving electrode remote from the piezoelectric material layer, wherein a thickness of the first sub-driving electrode is less than a thickness of the second sub-driving electrode. 
 
     
     
       9. The fingerprint recognition module according to  claim 1 , further comprising: a plurality of driving circuits electrically connected to the plurality of receiving electrodes in a one-to-one correspondence, wherein each of the plurality of driving circuits comprises:
 a storage capacitor comprising a first electrode and a second electrode; 
 a first thin film transistor comprising a first gate, a first source, and a first drain; and 
 a signal reading sub-circuit, configured to read a fingerprint electrical signal stored in the storage capacitor, 
 wherein for each driving circuit, a receiving electrode electrically connected to the each driving circuit is electrically connected to the first source and the first electrode. 
 
     
     
       10. The fingerprint recognition module according to  claim 9 , wherein the signal reading sub-circuit comprises:
 a second thin film transistor comprising a second gate electrically connected to the first electrode of the storage capacitor, a second source configured to receive a fixed voltage, and a second drain; and 
 a third thin film transistor, comprising a third gate configured to receive a read instruction signal, a third source electrically connected to the second drain, and a third drain configured to output an electric signal corresponding to the fingerprint electrical signal. 
 
     
     
       11. The fingerprint recognition module according to  claim 10 , further comprising:
 a plurality of multiplexers, each of which is configured to select and output the electrical signal corresponding to the fingerprint electrical signal; 
 a plurality of groups of data signal lines, each of which comprises multiple data signal lines, wherein the plurality of groups of data signal lines are electrically connected to the plurality of multiplexers in one-to-one correspondence, and each of the multiple data signal lines is electrically connected to third drains of third thin film transistors of a plurality of driving circuits arranged along the first direction; 
 a control circuit electrically connected to the plurality of multiplexers and configured to control the plurality of multiplexers to select and output the electrical signal corresponding to the fingerprint electrical signal; 
 a plurality of gate lines, each of which is electrically connected to third gates of third thin film transistors of a plurality of driving circuits arranged along the second direction; and 
 a gate driving circuit electrically connected to the plurality of gate lines and configured to provide the read instruction signal. 
 
     
     
       12. The fingerprint recognition module according to  claim 10 , further comprising:
 a plurality of gate driving circuits, each of which is configured to provide the read instruction signal; 
 a plurality of groups of gate lines, each of which comprises a plurality of gate lines, wherein the plurality of groups of gate lines are electrically connected to the plurality of gate driving circuits in one-to-one correspondence, and each of the plurality of gate lines is electrically connected to third gates of third thin film transistors of a plurality of driving circuits arranged along the first direction; and 
 a plurality of data signal lines, each of which is electrically connected to third drains of third thin film transistors of a plurality of driving circuits arranged along the second direction. 
 
     
     
       13. A display device, comprising: the fingerprint recognition module according to  claim 1 . 
     
     
       14. A driving method for a fingerprint recognition module, the fingerprint recognition module comprising: a receiving electrode layer comprising a plurality of receiving electrodes arranged in an array along a first direction and a second direction intersecting with the first direction; a piezoelectric material layer disposed on a side of the receiving electrode layer; and a driving electrode layer disposed on a side of the piezoelectric material layer remote from the receiving electrode layer and comprising a plurality of driving electrodes arranged along the second direction, wherein each of the plurality of driving electrodes is a strip electrode extending along the first direction, and an orthographic projection of the each of the plurality of driving electrodes on the piezoelectric material layer at least partially overlaps with an orthographic projection of multiple receiving electrodes arranged along the first direction on the piezoelectric material layer; the plurality of receiving electrodes comprise a plurality of receiving electrode groups arranged along the second direction, wherein each of the plurality pf receiving electrode groups comprises at least two receiving electrodes arranged along the first direction; and the orthographic projection of the each of the plurality of driving electrodes on the piezoelectric material layer at least partially overlaps with an orthographic projection of least two of the plurality of receiving electrode groups on the piezoelectric material layer; a minimum arrangement period of the plurality of driving electrodes arranged along the second direction is substantially equal to half a wavelength of an ultrasonic wave emitted from the fingerprint recognition module during operation; and
 the driving method comprising: 
 applying a driving voltage to a driving electrode so as to drive a portion of the piezoelectric material layer corresponding to the driving electrode to emit an ultrasonic wave; and 
 receiving the ultrasonic wave reflected by a fingerprint using the piezoelectric material layer and outputting a corresponding fingerprint electrical signal by a receiving electrode. 
 
     
     
       15. The driving method for the fingerprint recognition module according to  claim 14 , wherein the plurality of driving electrodes comprise a first driving electrode and a second driving electrode, and the driving method comprises:
 applying the driving voltage to the first driving electrode at a first time point so as to drive a portion of the piezoelectric material layer corresponding to the first driving electrode to emit an ultrasonic wave; and 
 applying the driving voltage to the second driving electrode at a second time point after the first time point so as to drive a portion of the piezoelectric material layer corresponding to the second driving electrode to emit an ultrasonic wave, a phase of which is delayed from a phase of the ultrasonic wave emitted from the portion of the piezoelectric material layer corresponding to the first driving electrode. 
 
     
     
       16. The driving method for the fingerprint recognition module according to  claim 14 , wherein the plurality of driving electrodes comprise a first driving electrode, a second driving electrode, and a third driving electrode, the second driving electrode is located between the first driving electrode and the third driving electrode, and the driving method comprises:
 applying the driving voltage to the first driving electrode and the third driving electrode at the first time point so as to drive a portion of the piezoelectric material layer corresponding to the first driving electrode and the third driving electrode to emit an ultrasonic wave; and 
 applying the driving voltage to the second driving electrode at the second time point so as to drive a portion of the piezoelectric material layer corresponding to the second driving electrode to emit an ultrasonic wave, a phase of which is delayed from a phase of the ultrasonic wave emitted from the portion of the piezoelectric material layer corresponding to the first driving electrode and the third driving electrode. 
 
     
     
       17. The driving method for the fingerprint recognition module according to  claim 14 , wherein the fingerprint recognition module further comprises: a plurality of driving circuits electrically connected to the plurality of receiving electrodes in a one-to-one correspondence, and each of the plurality of driving circuits comprises: a storage capacitor comprising a first electrode and a second electrode; a first thin film transistor comprising a first gate, a first source, and a first drain; and a signal reading sub-circuit, wherein for each driving circuit, a receiving electrode electrically connected to the each driving circuit is electrically connected to the first source and the first electrode, and wherein the receiving the ultrasonic wave reflected by the fingerprint using the piezoelectric material layer and outputting the corresponding fingerprint electrical signal through the receiving electrode comprises:
 applying a turn-on signal to the first gate to turn on the first thin film transistor when the driving voltage is applied to the driving electrode so as to drive the portion of the piezoelectric material layer corresponding to the driving electrode to emit the ultrasonic wave; 
 applying a bias voltage to the first drain according to an arrival time of the ultrasonic wave being reflected back to the piezoelectric material layer so as to raise the fingerprint electrical signal on the receiving electrode, and store a raised fingerprint electrical signal in the storage capacitor; and 
 reading out the raised fingerprint electrical signal using the signal reading sub-circuit. 
 
     
     
       18. A manufacturing method for a fingerprint recognition module, comprising:
 providing a substrate; 
 forming a receiving electrode layer on a side of the substrate, wherein the receiving electrode layer comprises a plurality of receiving electrodes arranged in an array along a first direction and a second direction intersecting with the first direction; 
 forming a piezoelectric material layer on a side of the receiving electrode layer remote from the substrate; and 
 forming a driving electrode layer on a side of the piezoelectric material layer remote from the receiving electrode layer, wherein the driving electrode layer comprises a plurality of driving electrodes arranged along the second direction, 
 wherein each of the plurality of driving electrodes is a strip electrode extending along the first direction, and an orthographic projection of the each of the plurality of driving electrodes on the piezoelectric material layer at least partially overlaps with an orthographic projection of multiple receiving electrodes arranged along the first direction on the piezoelectric material layer; the plurality of receiving electrodes comprise a plurality of receiving electrode groups arranged along the second direction, wherein each of the plurality of receiving electrode groups comprises at least two receiving electrodes arranged along the first direction; and the orthographic projection of the each of the plurality of driving electrodes on the piezoelectric material layer at least partially overlaps with an orthographic projection of least two of the plurality of receiving electrode groups on the piezoelectric material layer; a minimum arrangement period of the plurality of driving electrodes arranged along the second direction is substantially equal to half a wavelength of an ultrasonic wave emitted from the fingerprint recognition module during operation.